Bright gamma-ray burst tests idea of event’s origins

The maps in this animation show how much brighter gamma-ray burst GRB 130427A was relative to the rest of the gamma rays in the sky. The left map shows the sky during a three-hour period prior to the outburst. The right map shows a three-hour period from 2.5 hours before the burst to 30 minutes into the event.

High-energy light particles from one of the brightest gamma-ray burst observed to date suggest that physicists need to revise their theories explaining the origin of these cosmic blasts.

Gamma-ray bursts are the brightest events known to occur in the universe. Most scientists believe the high-energy bursts happen when gigantic stars explode as supernovas. The explosions send out shock waves that speed up nearby matter, causing a type of radiation called synchrotron radiation.

But observations of the gamma-ray burst GRB 130427A, which lasted 20 hours starting on April 27, 2013, revealed high-energy light particles too powerful to be produced by shock waves speeding up matter, scientists report November 21 in Science Express.